BioChem 3312 Exam 1

A glycosidic bond is

A bond between an anomeric carbon atom and any -OR group

Which of the following does not undergo oxidation-reduction reactions?

ATP

The enzymes of the oxidative phosphorylation system are located in the

Cristae of the Mitochondria

The pathway followed by glucose when energy is needed

Glycolysis

Around 80% of Starch is made up of branched amylopectin

True

Humans can not digest branched cellulose because we do not synthesize the enzyme that hydrolyzes the beta-1,4 or beta-1,6 bonds along the chain

True

How many electrons are needed to fully reduce the coenzyme NAD+ to NADH/H+

2

How many high-energy bonds (phosphoanhydride bonds) does ATP contain?

2

ATP, the energy transporter of the cell, contains ____ high-energy phosphoanhydride bonds. The hydrolysis of ATP to ADP _____ energy of 7.3 kcal/mol

2, releases

The overall yield of ATP molecules from the complete catabolism of one molecule of glucose in human and other mammals is

32

How many reduced coenzymes are produced from the two carbons introduced into one round of the citric acid cycle?

4

How many stereoisomers of an aldosterone can exist?

4

Which of the following reactions is the least energetic?

AMP + H2O to give Adenosine + Pi

What is the "energy currency" in Metabolism

ATP

The common molecule produced from all foods at the second stage of catabolism is:

Acetyl-CoA

The molecule that links carbohydrate and lipid metabolism is ____

Acetyl-CoA

When energy is needed and adequate oxygen is available, pyruvate is converted to _____

Acetyl-SCoA

Which chemical is produced from pyruvate it is metabolized in muscle cells under aerobic conditions

Acetyl-SCoA

Glucose can be classified as a(n)

Aldohexose

Ribose can be classified as a(n)

Aldopentose

Starch is composed of two polymers, ____, which is an unbranched chain, and ____ which is a branched polymer

Amylose; amylopectin

The biochemical process in which simple molecules are combined to make larger ones and energy is consumed is referred to as _____

Anabolism

Glycogen is produced by ___, and its major function is ___

Animals; energy storage

The biochemical process in which complex molecules are broken down into simpler ones and energy is released is referred to as

Catabolism

The biochemical process in which complex molecules are broken down into simpler ones and energy is released referred to as

Catabolism

Which polysaccharide has only beta-1,4 glycosidic linkage?

Cellulose

The mitochondria are the location where ____ takes place and most ____ is produced

Citric acid cycle; ATP

Except for ___, all fixed complexes of the electron transport chain pumps proteins from the matrix to the inter membrane space as they transfer electrons amongst each other

Complex V (ATP synthesis)

Glycolysis occurs mainly in the

Cytosol of all cells

Which sequence illustrates the order of the steps from food to biochemically useful energy?

Digestion; acetyl-SCoA production; citric acid cycle; ATP production

Phosphorylation reactions involve the addition of a phosphate group to a molecule. Such reactions are _____ reactions and therefore____

Endergonic; require energy

Shown above is the Photosynthesis reaction. The reverse reaction of photosynthesis would be a(n) _____ reaction with deltaG= _____kcal/mol

Exergonic; -686

Ketoenol tautomerism results in the conversion of an aldose to a ketose

False (ketose to aldose

A sugar present in honey in a 50/50 ratio with glucose is

Fructose

In steps 5-8 of the citric acid cycle, the high-energy molecules ___,___, and ___ are produced, and ___ is regenerated to begin another turn of the cycle

GTP, FADH2, NADH/H+, oxaloacetate

Which of the following carbohydrates can also be used as fuel in glycolysis?

Galactose, fructose, and mannose

The process of making glucose from noncarbohydrate is known as

Gluconeogensis

Which conversion is accomplished during glycolysis

Glucose to pyruvate

Mutarotation is a process where

Glucose undergoes reaction to form an equilibrium mixture of anomers

In N-linked glycoproteins, the sugar is usually attached to the protein by a bond to the N-atom in a protein side-chain. Which amino acid below can form such a bond

Glutamine

Glycogenolysis can be correctly represented by which of the following pathways

Glycogen to glucose

Which pathway produces glucose from its storage form in animals

Glycogenolysis

In an individual who is starving or fasting, the body meets its needful glucose by the first process of ____, and then by the process of ____

Glycogenolysis; gluconeogenesis

The pathway followed by glucose when energy is needed is

Glycolysis

Glycoproteins are formed by an oligosaccharide to a protein through a ____

Glycosidic

When a monosaccharide forms a ring by interaction of one of its hydroxyl groups with its aldehyde group, the bond is referred to as a(n) ____ linkage

Hemiacetal

All of the following chemicals except ___ provide protection against potentially harmful oxygen spices

Hydrogen peroxide

The reaction in which ATP is converted to ADP with released of 7.3 kcal is (an) ____

Hydrolysis

A lack of insulin causes ____, a state in which the concentration of blood sugar is ___

Hyperglycemia; higher

When blood sugar levels are lower than normal, this condition is called

Hypoglycemia

Overproduction of insulin causes ___, a state in which the concentration of blood sugar is ___ than normal

Hypoglycemia; Lower

When a person is deprived of food, in which order does the body use the following sources to produce glucose? i. Protein breakdown to amino acids for gluconegenesis ii. Conversion of glycogen to glucose iii. catabolism of lipids

II, I, III

The proton translocating ATP synthase in located in the

Inner membrane of the mitochondrion

The disease identified as diabetes are primarily associated with a malfunction of the hormone

Insulin

The pain and cramps that occur during physical exhaustion are associated with the formation of excess

Lactate

A metabolic pathway that can be illustrated as A-->B-->C-->D--> is said to be a(n)

Linear

Gluconeogenesis occurs mainly in the

Liver

The sum of all the biochemical reactions occurring in an organism is

Metabolism

The cellular organelle associated with energy production is the

Mitochondria

The major products of carbohydrate digestion are

Monosaccharides

ATP synthesis is driven by_____

Movement of H+ ions from the inter membrane space into the mitochondrial matrix

Glycogen is most commonly found in___ cells and ___ cells

Muscle; liver

Which statement is true concerning the relationship between NAD+ and NADH

NAD+ is the oxidized form of NADH

Exergonic reactions are those that have a _____ value of deltaG and ____ spontaneous

Negative; are

Every turn of the citric acid cycle directly produces ___ molecules of ATP

One

Every turn of the citric acid cycle directly produces ____ molecules of ATP

One

____ of glucose leads to gluconic acid

Oxidation

The process of converting ADP to ATP in the mitochondrion takes place by a process known as

Oxidative phosphorylation

Cellulose is produced by ___, and its major function is ___

Plants; as a structural component

Starch is produced by ___, and its major function is ____

Plants; energy storage

Endergonic reactions are shoes that have a ____ Values of delta G are ____ spontaneous

Positive; are not

In addition to producing ATP, the citric acid cycle produces ____ as high energy molecule and ___ as its major chemical waste product

Reduced conenzymes; CO2

The electron transport chain____

Reduces O2 to H2O

Which of the following monosaccharides is present in nucleic acids?

Ribose

The target molecule(s) for a-amylase is (are)

Starch and glycogen

When ATP is produced by direct transfer of a phosphate group instead of from reactions coupled to electron transport, the process is referred to as ____ phosphorylation

Substrate-level

All of the following sugars are reducing sugars except Glucose Maltose Sucrose Lactose No Exception. All of the above are reducing sugars

Sucrose

Harmful byproducts of biochemical oxidation include

Superoxide ions and hydroxyl free radicals

Harmful byproducts of biochemical oxidation includes

Superoxide ions and hydroxyl free radicals

The ultimate source of energy for all but a very few biochemical reactions is

The Sun

Acetyl-SCoA is an intermediate in the metabolism of food molecules. Which of the following, in AcetylCoA, is the metabolically functional group that enters the citric acid cycle?

The acetyl group

The driving force which provides the energy for synthesis of ATP in the fourth stage of metabolism is

The concentration gradient of hydrogen ions between the two sides of the inner mitochondrial membrane

The fourth stage of metabolism, in which the high energy molecule from stage three are oxidized to produce ATP is referred to as

The electron transport chain

The purpose of coupling two biochemical reactions are

Use an exergonic reaction to drive an endergonic reaction

The purpose of coupling two biochemical reactions is to

Use an exergonic reaction to drive an endergonic reaction

After O2 has been reduced in the electron transport chain, the oxygen atoms are part of what molecules?

Water

The cyclic structure is the

a-D-fructose

Alpha-D-glucose and Beta-D-glucose are

anomers

Hormones which regulate glucose metabolism are ___, ___, and ___

insulin, glucagon, epinephrine

The metal that acts as an electron carrier in the cytochrome in the electron transport chain is

iron

In a coupled reaction, such as in the example shown, if the exergonic reaction releases more energy than the amount required by the endergonic reaction, the excess is _____

released as heat and used to maintain body temperature